FIELD OF THE INVENTION
In the most general terms, the present invention relates to communicating as well as storing and retrieving sequences of images, and more particularly to procedures and devices for compressing the information used to transmit or store a sequence of images. It compresses the information by efficiently encoding both the spatial redundancy i.e. the redundant information present among groups of picture elements ("pixels") of each image ("frame") and the temporal redundancy that exists from frame to frame. In addition to this, the present invention further compresses the information by selectively deleting information whose loss does not materially affect the quality of the sequence of images decoded from the compressed data.
Although the information generated by this invention and by the prior art is applicable to storage and retrieval as well as transmission and reception, for clarity, the descriptions will be in terms of transmission and reception. Applying the concepts to storage and retrieval will be obvious.